Explain when the french use the prepositions à, au, and en in front of destinations.

- If the destination is a city, we use the preposition 'to' before the name of the city but we sometimes use the preposition 'in' before the name of a town beginning with 'The' (Le Havre)
Ex : I go to Paris.

-If the destination is a country we use the preposition 'to' before a masculine noun, 'the' in front of a masculine plural noun but 'to' before a singular noun.
Ex: I am going to Japan.
I am going to the U.S.
I go to Germany.
I'm going to France.

Can you give a list then i can choose the best answer